380 HISTORY OF THE THEOEY OF NUMBEKS. [CHAP, xv A. Ge*rardin61 noted that Fn==(240s+97)(240i/+161) for all the Fn fully factored to date, and specified x and y more exactly in special cases. C. Henry*2 gave references and quoted known results. R. D. Carmichael63 gave a test for the primality of Fn equivalent to Pepin's19 and a further generalization (p. 65) in the direction of Hurwitz's.41 R. C. Archibald64 cited many of the papers listed above and collected in a table the known factors of Fn with the exception of that given by Morehead.61 For a remark on Fn, see Cunningham101 of Ch. VII. "Sphinx-Oedipe, 7, 1912, 13. "Oeuvres de Fermat, 4, 1912, 202-4. "Annals of Math., (2), 15, 1913-4, 67. "Amer. Math. Monthly, 21, 1914, 247-251.